I'm a bit confused about the iCloud support. It seems rather limited in that while it works quite well for what it is, well, it seems awfully limited. I move file to iCloud and they land in a list, sortable in OS 10.8, not so much in 10.7. There doesn't seem to be any kind of way of making a folder structure or any other way of managing that list of files. Is this an Apple thing, a Mellel thing or am I just missing an obvious "new folder" command? My file file list is getting long and is an unholy mess on OS 10.7.

It's not a Mellel thing, it's an Apple thing. The problem with iCloud is that applications (and their data stores) are isolated from one another. So, only another copy of Mellel linked to your same iCloud account can see any of the documents you've created in iCloud in Mellel.

Think of it as functioning similar to Apple's iOS devices: Each application has no clue about any other application, and cannot see or share information with other applications, except through specific points that Apple allows. This "sandboxing" is one of the reasons I feel that iCloud is a step backwards: applications are relegated to their own silos, and they can't share. If you create an RTF in one app's iCloud data store, you cannot open it in another application that understands RTF, because it doesn't know that it exists.

Personally, I would recommend avoiding iCloud and use a different cloud-based document-based syncing option, as iCloud is far too limiting.

More on the whole iCloud thing. I'm thinking this is more Apple sandboxing but it doesn't make a whole lot of sense to me. I've got a couple computers one running 10.9.5 and the other running 10.10.idon'tremember. Both machines have Mellel 3.3.8.

Why can't the 10.10 machine see the files the 10.9.5 machine puts on iCloud? Does Apple sandbox by app and OS version?

Also the newer version can't see the older version so if I upgrade the 10.9.5 machine to 10.10 will I lose access to the files uploaded by 10.9.5? That seems insane.

If you upgraded to iCloud Drive on any iOS 8 or OS X 10.10 machines, but still have devices on earlier versions of iOS or OS X, then you're in a bit of a mess. The conversion is one-way, and applications on earlier systems trying to access iCloud will mess things up, because you're using 'iCloud Drive', which is similar yet is still different. The dialog asking if you wanted to upgrade made it clear that this was the case.

Unfortunately, there really is no remedy; your iCloud account is forever changed. Your only real option is to upgrade to 10.10, which is supported on every Mac that can run 10.9, and to upgrade all your iOS 7 devices to 8.